The Food and Drug Administration announced today that regulators are assessing at least 32 reports of liver problems between 1999 and 2008 in patients taking the weight-loss drug orlistat, sold as a prescription drug Xenical and more recently, as an over-the-counter medication called Alli.

Of the 32 reports of liver problems the FDA has in hand, 27 patients were hospitalized and six suffered liver failure. In an "early communication" of a drug safety review, the FDA said it will also review additional data on "suspected cases of liver injury" submitted by drug firms that make and market orlistat in its branded and generic forms. Orlistat was originally marketed, and still is, by Roche Pharmaceuticals as Xenical, a prescription drug. The medication, which blocks the absorption of fat through the digestive tract, gained approval as an over-the-counter drug in 2007, and is marketed as Alli by GlaxoSmithKline. Orlistat has been approved for use in 100 countries.